The casino does have the right to modify or add new terms and conditions without agreement with the user, but the new policy must not be detrimental to the user, the casino still acts fairly and is responsible for paying the jackpot withdrawal without making it difficult for any reason. We may not be able to do anything if the casino decides to unilaterally harm the user, but we have control to report the casino to the community by including valid evidence, the casino will lose its users because gamblers do not use casinos that harm users, without users gambling will not operate and slowly the casino will go bankrupt unless the casinos fix everything before the big trouble comes along.